在 mol2chemfig 中制作双头机制箭头

Question

我想使用双头机制箭头来指示羰基键随着离去基团的排出而断裂和重新形成。

我迄今为止的代码：

\documentclass[12pt,a4paper]{article}
\usepackage{chemformula}
\usepackage{mol2chemfig}
\usetikzlibrary{arrows}
\colorlet{mcfpusharrowcolor}{red}%<----- Added to change the color of the curved arrows

%\tikzset{ 
 %   }

\setchemfig{bond offset=1pt,atom sep=2em,compound sep=5em,arrow offset=10pt,arrow coeff=1.25}
\usepackage[margin=1.5cm]{geometry}

\begin{document}
\section*{Claisen Condensation}
\begin{center}
\schemestart
\chemfig{
          % 1
    -[:30]% 2
             (
       -[:330]OEt% 3
             )
    =[:90]O% 4
}
\arrow{<=>[\ch{NaOEt}][]}
\chemfig{
           % 1
     =[@{DB}:30]% 2
              (
         -[@{OCB}:90]\mcfright{O}{^{\ominus}}@{OM}% 4
              )
    -[:330]OEt% 3
}
\arrow{<=>[\chemfig{
           % 1
    -[:30]@{CC}% 2
             (
       -[@{COET}:330]@{OET}OEt% 3
             )
    =[@{ODB}:90]@{O}O% 4
}][]}[,2]
\chemfig{
           OEt% 2
    -[:150]% 1
              (
         =[:90]O% 3
              )
    -[:210]% 4
              (
        -[:240]H% 8
              )
              (
        -[:295]H% 9
              )
    -[:150]% 5
              (
         =[:90]O% 6
              )
    -[:210]% 7
}
\arrow{<->>[\chemfig{^{\ominus}OEt}][]}[-90]
\chemleft[\subscheme{
\chemfig{
           % 1
     -[:30]% 2
              (
         =[:90]O% 6
              )
    -[:330]% 3
     =[:30]% 4
              (
         -[:90]\mcfright{O}{^{\ominus}}% 7
              )
    -[:330]OEt% 5
}\arrow{<->}
\chemfig{
          % 1
     -[:30]% 2
              (
         -[:90]\mcfright{O}{^{\ominus}}% 6
              )
    =[:330]% 3
     -[:30]% 4
              (
         =[:90]O% 5
              )
    -[:330]OEt% 7
}}\chemright]
\arrow{->[\chemfig{H_3O^{\oplus}}][]}[180]
\chemfig{
           % 1
     -[:30]% 2
              (
         =[:90]O% 6
              )
    -[:330]% 3
     -[:30]% 4
              (
         =[:90]O% 5
              )
    -[:330]OEt% 7
}
\schemestop
\end{center}

\begin{tikzpicture}[mcfpusharrow/.style = {
        mcfpusharrowcolor,
        shorten <=1pt,
        shorten >=2pt}
        ]
\mcfpush{DB}{100:25mm}{CC}{150:8mm}
\mcfpush{OM}{-45:8mm}{OCB}{-45:5mm}
\mcfpush{ODB}{-45:4mm}{O}{-45:8mm}
\mcfpush{COET}{90:5mm}{OET}{90:5mm}
\end{tikzpicture}
\end{document}

谢谢你的协助！

Answer 1

我建议将箭头放入不​​同的tikzpicture环境中，这样您就可以mcfpusharrow/.style只更改这一个箭头而不会影响其他箭头：

\documentclass[12pt,a4paper]{article}
\usepackage{chemformula}
\usepackage{mol2chemfig}
\usetikzlibrary{arrows}
\colorlet{mcfpusharrowcolor}{red}%<----- Added to change the color of the curved arrows

\setchemfig{bond offset=1pt,atom sep=2em,compound sep=5em,arrow offset=10pt,arrow coeff=1.25}
\usepackage[margin=1.5cm]{geometry}

\begin{document}
\section*{Claisen Condensation}
\begin{center}
\schemestart
\chemfig{
          % 1
    -[:30]% 2
             (
       -[:330]OEt% 3
             )
    =[:90]O% 4
}
\arrow{<=>[\ch{NaOEt}][]}
\chemfig{
           % 1
     =[@{DB}:30]% 2
              (
         -[@{OCB}:90]\mcfright{O}{^{\ominus}}@{OM}% 4
              )
    -[:330]OEt% 3
}
\arrow{<=>[\chemfig{
           % 1
    -[:30]@{CC}% 2
             (
       -[@{COET}:330]@{OET}OEt% 3
             )
    =[@{ODB}:90]@{O}O% 4
}][]}[,2]
\chemfig{
           OEt% 2
    -[:150]% 1
              (
         =[:90]O% 3
              )
    -[:210]% 4
              (
        -[:240]H% 8
              )
              (
        -[:295]H% 9
              )
    -[:150]% 5
              (
         =[:90]O% 6
              )
    -[:210]% 7
}
\arrow{<->>[\chemfig{^{\ominus}OEt}][]}[-90]
\chemleft[\subscheme{
\chemfig{
           % 1
     -[:30]% 2
              (
         =[:90]O% 6
              )
    -[:330]% 3
     =[:30]% 4
              (
         -[:90]\mcfright{O}{^{\ominus}}% 7
              )
    -[:330]OEt% 5
}\arrow{<->}
\chemfig{
          % 1
     -[:30]% 2
              (
         -[:90]\mcfright{O}{^{\ominus}}% 6
              )
    =[:330]% 3
     -[:30]% 4
              (
         =[:90]O% 5
              )
    -[:330]OEt% 7
}}\chemright]
\arrow{->[\chemfig{H_3O^{\oplus}}][]}[180]
\chemfig{
           % 1
     -[:30]% 2
              (
         =[:90]O% 6
              )
    -[:330]% 3
     -[:30]% 4
              (
         =[:90]O% 5
              )
    -[:330]OEt% 7
}
\schemestop
\end{center}

\begin{tikzpicture}[mcfpusharrow/.style = {
        mcfpusharrowcolor,
        shorten <=1pt,
        shorten >=2pt}
        ]
\mcfpush{DB}{100:25mm}{CC}{150:8mm}
\mcfpush{OM}{-45:8mm}{OCB}{-45:5mm}
\mcfpush{COET}{90:5mm}{OET}{90:5mm}
\end{tikzpicture}
\begin{tikzpicture}[mcfpusharrow/.style = {
        mcfpusharrowcolor,
        shorten <=1pt,
        shorten >=2pt,
        <->,                               % <--- Double ended arrow
        >=stealth}                         % <--- Same style as other arrows in he diagram
        ]
\mcfpush{ODB}{-45:4mm}{O}{-45:8mm}
\end{tikzpicture}
\end{document}

要调整箭头大小，您可以使用scale如下所示的选项，或者使用 、 、 、 或length16.3.1width和inset16.3.2angle节（第 190-193 页）中描述的scale lengthscale widthPGF 手册

\begin{tikzpicture}[mcfpusharrow/.style = {
        mcfpusharrowcolor,
        shorten <=1pt,
        shorten >=2pt,
        {Stealth[scale=1.5]}-{Stealth[scale=1.5]},}  % <--- Double ended arrow, same style as others, scaled arrow tips
        ]
\mcfpush{ODB}{-45:4mm}{O}{-45:8mm}
\end{tikzpicture}